The misuse of alcohol is the major preventable contributor to death and injury for adolescents and young adults. Early adolescence remains a time of high vulnerability for initiating alcohol use and there are prevention opportunities that can be realized by better understanding the interrelationships between individual development influences such as puberty and societal, school and family contexts. This three year proposal provides a unique opportunity to investigate the impact of both individual differences and context on alcohol use during late childhood and early adolescence. The International Youth Development Study (IYDS) collected data in 2002 from 5,769 students in three cohorts (approximately 1,000 students in Grades 5, 7, and 9) using matched procedures and recruitment of state wide representative samples in Washington state and Victoria, Australia. Each cohort was followed over two and three years resulting in a sample with an age span from age 10 to age 16 years. We propose to examine similarities and differences in predictors of alcohol use, misuse and other problems. The data collected for the IYDS study is of a high quality and was designed to compare the epidemiology and etiology of adolescent alcohol and drug use, abuse, and other related behavior problems in two states selected for their many similarities, yet contrasting cultural and policy orientations toward youth alcohol and drug use. One- year follow-up (and two-year follow-up of the Grade 7 cohort) yielded student resurvey rates of over 98 percent in both states. Student reports were supplemented with a parent telephone interview and three school administrator reports of the policy context of participants'schools. The original grant (NIDA: R01-DA012140) enabled only limited analysis and reporting, hence there are valuable contributions to the understanding of adolescent alcohol use that can be published through further exploration of this data. The analyses will yield new information on the local and cross-national influences on early adolescent alcohol use and symptoms of alcohol use disorders, enabling the cultural generalization of risk influences and alcohol consequences to be investigated. The influence of environment (e.g., school policy, family alcohol practices, socioeconomic status and rural location) will be explored together with the effects of individual influences (e.g., pubertal development, behavior, personal adjustment and attitudes). This project will also yield publications exploring the short-term impact of early alcohol use on symptoms of alcohol use disorders, suicidal behavior, depression, academic achievement and pro-social development. A unique comparative analysis of different theoretical explanations for the influence of early age alcohol use on the development of alcohol use disorder symptoms will also be investigated. The project will be completed by two teams that have a track record of successful research and collaboration. The identification of modifiable influences in areas such as school policy and family practices has the potential to provide new directions for preventing early adolescent alcohol use and misuse. This project will examine similarities and differences in predictors of alcohol use and misuse of substances in representative samples of youth from two states (Washington and Victoria, Australia). Analyses will help identify modifiable influences such as school policy and family practices that can be used to prevent these problems of primary importance to the public health community.